Prepackaged buoyancy system

ABSTRACT

A prepackaged buoyancy system incorporating a hydrazine gas generator between upper and lower portions of a lifting assembly which are separably connected by a fabric airtight bag such that when the hydrazine generator produces a gas the upper portion is caused to separate from the lower portion to produce a gas filled lifting device.

United States Patent lnventor Donald Miller China Lake, Calif.

Appl. No. 779,166

Filed Nov. 26, 1968 Patented Jan. 19, 1971 Assignee the United States of America as represented by the Secretary of the Navy PREPACKAGED BUOYANCY SYSTEM [5 6] References Cited UNITED STATES PATENTS 3,322,088. 5/1967 Harada et a1. 114/54 Primary Examiner-Andrew H. Farrell Attorneys-Edgar J. Brower and Roy Miller ABSTRACT: A prepackaged buoyancy system incorporating a hydrazine gas generator between upper and lower portions 1 Claim 2 Drawing Figs of a lifting assembly which are separably connected by a fabric US. Cl 114/54 airtight bag such that when the hydrazine generator produces B63c 7/10 a gas the upper portion is caused to separate from the lower Field of Search 1 14/54 portion to produce a gas filled lifting device.

2 2| l5 H ZLZI l1 IV 4 fl 1 l6 I L2 1 2s 1 t o g Q 19 4 x I I0 h 24 2s i I b 3| IPATENTEULJANISIBYI 3555034 FIG. I.

v YINVENTOR. DONALD MILLER ROY MILLER ATTORNEY.

PREPACKAGEDBUOYANCY SYSTEM GOVERNMENT INTEREST The invention described herein'may be manufactured-and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

. BACKGROUND OF THE INVENTION The invention is concerned with providing a lifting device for recovery of objects from and below diver depths. Heretofore, lifting bags which are ordinarily filled from an air bottle, CO cartridges used in conjunction with the elastic bags and other crude devices have been used to recover objects at diver depths in an ocean environment. The main disadvantages with these devices have been that they are depth limited and ordinarily they don't function.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross section through the prepackaged buoyancy system illustrating a preferred embodiment of the invention;

and

FIG. 2 is a side elevation of thebuoyancy system illustrating the configuration.

DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred embodiment, as shown in FIG. 1, comprises a lower section and upper section '11 which are formed of a relatively hard material such as'fiberglass. Upper portion 11 is suitably secured to a lifting container end plate 12. Threadably attached to the upper portion 11 is a ball valve 13 having an actuating handle 14 secured thereto so that the ball valve may be turned from an open to a closed position under diver control. The bottom most portion of the check valve 13 is in open communications with a piston cavity 15.

The piston cavity 15 is formed from an assembly housing 16 and has a large diameter upper section and a smaller diameter or lower section. Contained within the piston cavity 15 is a monopropellant gas generator generally indicated at 17 which has an upper piston portion 18 adapted to move in the large diameter upper section of the piston cavity and a bottom piston portion 19 adapted to move in the smaller diameter lower section. The upper piston portion 18 and lower piston portion 19 are fitted with O-ring seals for a sealing relationship with the walls of the piston cavity. The upper portion of the piston 18 has secured thereto an exhaust port 20 having an exhaust port plate 21 on the ball valve side. Shell 405 catalyst generally indicated at 22 is contained between another e'ithaust plate 23 and a lower fuel inlet plate 24 which is in communication with a burst diaphragm 25. The burst diaphragm seals one end of the fuel container 26 which is contained around the bottom of the assembly housing 16 and threaded into the plate 27 is a lower lifting eye 28 having a collar 29 thereon which is seated against the lower housing portion 10.

The lifting container end plate'l2 has threa ably secured thereto one end of a lifting container 30. The other end of the lifting container is threadably secured to the lower housing portion 10. The lifting container comprises a fabric airtight bag in the present instance. I

The fuel container 26 may be any flexible container which is compatible with hydrazine, i.e., plastic bag, rollanet, etc.

Vent tubes indicated at 31 and 32 are in open communication with the exterior through the bottom portion 10 and the gas filled chamber which is formed by the lifting bag 30 or lifting container 30 when it is in extended position.

The normally open portion of the housing between the lower body portion 10 and the assembly housing 16 is filled with syntactic foam generally indicated at 33. Syntactic foam is a foam comprised of micron sized hollow glass, ceramic or plastic spheres (microballoons) on a plastic binder.

FIG. 2 illustrates the preferred embodiment of the invention in inflated position comprising lower body portion 10, lifting container 30 and the upper portion II.

In operation at depth, eyebolt 28 is attached to an object to be lifted and ball valve 14 actuated which allows sea water at ambient pressure to impinge on the large piston 18 an exhaust port plate 21. At this point, the ambient pressure will cause the large piston 18 to descend thereby causing the hydrazine contained in the flexible fuel container 26 to burst the burst diaphragm 25. The hydrazine will enter the catalyst bed 22 and become a gas. The gas pressure will rupture the exhaust port plate 21 and the gas will impinge on the lifting container end plate 11.

In that the ball valve 13 is closed at this point, the end plate 11 will be displaced causing the lifting container 30 to unfold.

The ports 32 allow excess gas to escape when the system rises so that the bag 30 does not rupture once the gas generator 17 goes into action.

Once the generator is activated the gas pressure which is generated is enough to cause the large piston 18 to keep descending, thereby causing the hydrazine to be expelled through the catalyst bed 10, generating more gas.

The differential-area piston fuel expulsion system which is used in the present invention was designed to use the ambient sea pressure against the large end of the differential-area piston thereby producing a 2.25 pressure gain in the fuel tank.

The present prepackaged buoyancy system is an all up system which is independent of surface support and which requires no explosive or electrical devices to initiate action. However, if it were desired, an explosive or electrical device could be used to initiate the ball valve which allows the sea water to impinge against the exhaust port plate thereby initiating action of the fuel in the catalyst. Other advantages of the present system are that neutral buoyancy is attained and the system is very inexpensive and simple to operate.

Iclaim:

1. A prepackaged buoyancy system comprising:

a housing having upper and lower portions;

the upper and lower portions being separably joined in a closed position when the buoyancy system is noninflated;

a monopropellant gas generator utilizing hydrazine as a fuel contained between the upper and lower portions adapted to produce a gas under control;

a monopropellant fuel section contained within said upper and lower portions of the housing;

extensible airtight means connecting said upper and lower portions adapted to contain a gas generated by the gas generator so that when the gas generator produces a gas the upper and lower portions separate to provide a gas filled buoyancy section; and

wherein said monopropellant gas generator is acted on at one end by the exterior hydrostatic pressure in such a fashion that the monopropellant gas generator is driven toward the fuel supply so that the fuel supply is forced through the gas generator thereby producing a gas. 

1. A prepackaged buoyancy system comprising: a housing having upper and lower portions; the upper and lower portions being separably joined in a closed position when the buoyancy system is noninflated; a monopropellant gas generator utilizing hydrazine as a fuel contained between the upper and lower portions adapted to produce a gas under control; a monopropellant fuel section contained within said upper and lower portions of the housing; extensible airtight means connecting said upper and lower portions adapted to contain a gas generated by the gas generator so that when the gas generator produces a gas the upper and lower portions separate to provide a gas filled buoyancy section; and wherein said monopropellant gas generator is acted on at one end by the exterior hydrostatic pressure in such a fashion that the monopropellant gas generator is driven toward the fuel supply so that the fuel supply is forced through the gas generator thereby producing a gas. 